The laboratory is devoted to studies investigating vagal and hormonal mechanisms effecting secretory and motor activity in the upper gastrointestinal tract. The role of the stomach's acid secretion, as well as antral-gastrin mechanisms, in the homeostasis compensating for metabolic acidosis is being investigated. Quantitation of antral gastrin cell populations in the dog's stomach in terms of a technique for accurate measurement, as well as alterations in numbers and concentration of G cells in response to a number of normally occurring and pharmacologic stimuli, are also being evaluated. The effect of intestinal bypass procedures on serum gastrin levels and acid secretion, with particular emphasis on the role of the small bowel in the degradation and elimination of gastrin is also investigated. Effects of varying degrees of retained antrum following gastric surgery, on gastric acid secretion and serum gastrin, is being studied in dogs. The role of the parasympathetic nervous system in augmenting the distortions caused by retained antrum is also being evaluated. Finally, the role of the renal parenchyma as well as the urinary excretory process is being studied in dogs in the anephric state, as well as those with chronic and acute renal failure.